It is known that a vehicle includes an air bag apparatus for protecting passenger. On the other hand, a pair of seat slide portions is provided at both the left and the right sides of a vehicle seat for adjusting a seat position in longitudinal direction of the vehicle.
When the air bag apparatus is operated with a certain amount of an operating force relative to the passengers, an effect of the air bag apparatus may be changed depending on the vehicle seat position (a position of the passenger). In other word, a preferred effect may not be obtained when the seat is away from the air bag apparatus. Then, it is proposed that the operating force for operating the air bag apparatus can be switched depending on the vehicle seat position. In addition, it is known that some vehicle seats include a seat position detecting apparatus for switching the operating force for operating the air bag apparatus.
An example of the known seat position detecting apparatus is shown in FIG. 7. The vehicle seat position detecting apparatus includes an object board 92 fixed at a lower rail 91 and a sensor 95 fixed at an upper rail 93 with a bracket 94. The seat slide portion includes the lower rail 91 and the upper rail 93. The upper rail 93 is provided slidably on the lower rail 91 in the longitudinal direction of the vehicle. The, sensor 95 has two vertical portions extending in vertical direction and houses a magneto-electric converting element 97 at one end thereof and a magnet 98 at the other end thereof.
Depending on the vehicle seat position, the object board 92 may be or may not be located between the magneto-electric converting element 97 and the magnet 98 (the position of the upper rail 93). When the object board 92 is located between the magneto-electric converting element 97 and the magnet 98, a magnetic force from the magnet 98 is blocked by the object board 92 and not applied to the magneto-electric converting element 97. On the other hand, when the object board 92 is not located between the magneto-electric converting element 97 and the magnet 98, the magnetic force from the magnet 98 is applied to the magneto-electric converting element 97 without blocking by the object board 92. Thus, the vehicle seat position detecting apparatus (sensor 95) can detect the vehicle seat position based on the magnetic force applied to the magneto-electric converting element 97. Thus, the magnetic force applied to the magneto-electric converting element 97 has been changed in response to the existence of the object board 92.
According to the known seat position detecting apparatus, the object board 92 is additionally needed at the lower rail 91, and the bracket 94 is additionally needed at the sensor 95 for detecting the object board 92. Furthermore, there is a need to save a space in which the object board 92 and the sensor 95 can move along the lower rail 91 and the upper rail 93. Thus a space under the vehicle seat is limited, and the mountability of the vehicle seat position detecting apparatus becomes worse.
A known seat position detecting apparatus in which the mountability is improved while the number of the members thereof is reduced is disclosed in Japanese Patent Laid-Open Publication published as No. 2002-20093. This disclosed seat position detecting apparatus detects the vehicle seat position by detecting the lower rail by a sensor portion provided at the upper rail.
In the configuration of the disclosed seat position detecting apparatus, however, the sensor portion is still provided with the bracket. In other words, the sensor portion is provided hanging over the lower rail. In addition, the sensor portion includes a L-shaped side surface and detects whether or not the lower rail is in a space formed by connecting two ends of the L-shaped side surface and an opposite corner relative to a corner of the L-shaped side surface in a cross-sectional view. Thus, the sensor detects the vehicle seat position depending on the magnetic force applied to the magneto-electric converting element. In this configuration, however, there is a need to save a space in which the sensor portion can moves along the lower rail in longitudinal direction of the vehicle. Thus a space under the vehicle seat is limited.
The current invention provides a seat position detecting apparatus, a rail position detecting apparatus and a movable body detecting apparatus which can improve the mountability of the position detecting means.